Flow heater



Oct. 1, 1957 J. CRNY 2,808,034

FLOW HEATER Filed May 25, 1954 2 Sheets-Sheet. 1

A INVENTOR. Josef: CER/yy Oct. 1, 1957 J. cERNY 2,808,034

l FLOW HEATER Filed May 25, 1954 v 2 sheets-sheen 2 INVENTOR. :VasaF C ERP/y BY United States Patentf ,v ,2,808,034 FLOW HEATER Josef Cerny, Vienna, Austria, assignor to Fa. Gas, Wasserund `Elektrische Anlagen Swatek & Cerny, Vienna, Austria Application May 25, 1954, Serial No. 432,259 Claimsrpriority, application Austria .lune 9, 1953 sentais. (c1. 122-32) The invention relates to allow heater which can be utilized, ifV desired, also as a hot-water or stem heating appliance, with a boiler which is heated by a gasor oilburning device, if desired also by a pulverized-coal burning device, and whose counterflow apparatus (reservoir) is arranged together with the boiler in a hot-water cycle, which either heats a heat exchanger, provided in the counterow apparatus, for water for consumption to be taken as required, or supplies Warm water to one or severalV Warm-water radiators which serve for room heating and which with their supply and discharge lines are connected to the delivery and return lines of the hot-water cycle and can be turned on and off as required. In those known llow heaters the reservoir is connected by conduit pipes to the boiler and is not heated. The heat transfer to the heat exchanger carrying the water for consumption is eiected by the hot water contained in the reservoir, which is supplied from the boiler through freely extending lines. In many cases a pump is used to maintain the circulation of hot water. Depending on its direction of rotation that pump conveys the hot water from the boiler either for heating the heat exchanger or for feeding the warm-water heating installation. Flow heaters are known in which the hot-water reservoir and the counterow apparatus are combined in a single set. In that case too the counterflow apparatus is not swept by the heating gases but is only flown through by the hot Water; thus it is not heated additionally. The absence of an additional heating of the reservoir or counterlow apparatus has the result that when relatively large quantities of water for consumption are taken the heat exchanger takes from the reservoir such an amount of heat energy that after the water for consumption has been taken the warm-water heating system returns only very slowly to the previously adjusted heat output.

For this reason the main idea underlying the invention is to utilize the heat of the boiler primarily for heating the counterow apparatus or reservoir and thus to increase the heating eiect to a maximum not achieved so far, and further to combine the heating of the water for consumption and the room heating by means of the counterflow apparatus in such a manner that the heating of the water for consumption and the room heating operate independently of each other but also simultaneously with the closest exible adaptation possible regarding the respective conditions of demand, without requiring for this purpose special shut-oi means or drive means such as pumps or the like.

According to the invention this idea is carried into effect by arranging the boiler, consisting of hollow heating elements having a large heat absorbing surface and small flow cross section, in the heating-gas stream in series with a heating-steam or hot-water reservoir which functions as a counterflow apparatus and contains the heat exchanger for heating the water for consumption, the boiler and the heating-steam or hot-water reservoir being included in a closed cycle of the steam or hot water, in which cycle the heating of the water for consumption is ice.

effected by means of the heat exchanger within the heating-steam or hot-water reservoir Whereas the room heating installation with its delivery and return lines may be connected in parallel to that cycle. A further measure according to the invention and of essential significance for the function of the ow heater resides in that the heat exchanger lies in the heating-steam or hot-water reservoir between the inlet for the steam or hot water and its return line and the delivery line of the room heating installation is attached to the heating-steam or hot-Water reservoir at a distance from the heating-steam or hotwater inlet, for the interposition of part of the heat exchanger serving as a temperature-reducing resistance, and that yclose to or directly at the fresh-water inlet of the heat exchanger and the beginning of the return line for the hot water a thermostat is arranged, which operates a control member controlling the fuel supply to the burner in dependence on the temperature variation in the inlet range of the cold water and elfective immediately when a temperature drop in the heating-:steam or hot- Water reservoir results from a taking of water for consumption, in order to compensate that temperature drop by setting the heating to a higher energy stage. Thus a heating appliance for warm Water and water for consumption lis provided, which automatically adjusts itself and very` flexibly responds to all conditions of demand and which utilizes the expended heat energy in a degree not hitherto achieved.

In the drawing the invention is shown in an illustrative embodiment in its essential features in Fig. l in conjunction with the use of a warm-water reservoir, in vertical section, and in Fig. 2 in a side view of the return-line side, with the casing and jacket in section. Figs. 3 and 4 show the boiler and burner in plan, according to horizontal sections C-D and E-F, respectively, of Fig. 5. Fig. 5 Ishows the arrangement of the pipe coil in conjunction with the use of a steam reservoir.

The flow heater serving for preparing Warm water and for heating water for consumption has a radiator-type heater, which consists, e. g., of six heating elements 1 having small flow cross sections and large heat absorbing surfaces. Each of the heating elements 1 consists of a flat casting, which is divided, e. g., by five vertically extending passage slots 2, into six water carrying conduits 3, which open at top and bottom into common collecting spaces. Each of said collecting spaces has a central connection tting 4 and 5, respectively. These heating elements 1 are connected in parallel in a hot-water ilow cycle, their lower connection ttings 4 being firmly and tightly iixed in direct succession on a pipe length 7 directly connected to the return pipe 6, and their upper connection ttings 5 being firmly and tightly fixed in a similar manner on a delivery pipe 8. The pipe length 7 and the delivery pipe 8 have radial bores through which they are in flow-communication with the cavities of the heating elements 1. The delivery pipe 8 is bent upwardly and opens at the top into the end of a hot-Water reservoir 9 effective as a heat accumulator. That hot-water reservoir consists of an outer shell 9 and an inner shell 10 of much smaller diameter, which encloses a water-free cavity 11 and together with the outer shell 9 forms a reservoir space 12 of annular cross section, into which flows the hot water from the delivery pipe 8. At the other end of the hot-Water reservoir 9, 12 the outlet pipe 13 is attached in the form of a fork continued in a single pipe which opens into one end of the pipe length 7 connected to the return pipe 6 to complete the closed hotwater cycle.

The return pipe 6 of the hot-water cycle lies horizontally in the same plane as the burner tube 14 just above the ksupporting base of the flow heater. The burner tube 14 is forked and intended, e. g., for gas tiring.

By the pipe 15 it is connected through a gas-burner cock 16 to the gas pressure control 17, which through the pipe length 18 is connected to the known safety cock 20 having a push button 19 and possessing the pilot burner 21 burning with a small flame and enabling the'supervision of the supply of gas from `the supply line 22. I

To avoid the formation of water of condensation the heater consisting of the heating elements 1, as well as the hot-water reservoir 9, 12 are arranged almost directly one above the other in a ireboX space 23, which being enclosed by a downwardly opening casing 24, surrounds the hot-water reservoir 9 with a slight clearance and has at the top an ottake 25. That casing 24 is surrounded with a clearance by a jacket 36, which permits scavenging air to ilow from below through the smoke iiue 37 and thus cools the casing 24 from the outside. That firebox casing 24 extends down to a horizontal plane just above the burner tube 14 to conduct the combustion gases upwardly along the heater 1 and the hot-water reservoir 9. To achieve a good utilization of the hot combustion gases, the heating elements 1 `have in their upper part below the connection fittings 5 horizontal battles 26 in a rooiiike arrangement, which guide the heating gases from the interspace between two heating elements through the oblong slots 2 into the adjacent interspace. Thus the heating gases are somewhat dammed up and deilected in the upper portion of the heating elements and are thus forced to deliver the largest possible part of their heat to the heater.

For the operation of a warm-water heating installation having several radiators for room heating, the hot-water reservoir is provided at its top with a riser pipe 27, an 'expansion vessel 28 and an overflow pipe 29 connected thereto. The supply line 30 to the radiators (not shown) is connected to the riser pipe 27. The return line (not shown) from the radiators opens .at the bottom into the return pipe 6.

A pipe coil 31 arranged in the hotwater reservoir 9, 12 serves for heating Water for consumption. The inlet 32 to and the outlet 33 from that coil are provided at that reservoir end wall which is adjacent to the outlet 13 for hot water from the reservoir 9. That pipe coil 31 is always maintained at the temperature desired at a given time, e. g. 80 deg. C., by the hot water in the reservoir 9, 12, and can deliver at any time hot water for consumption, e. g. for cooking and washing purposes. That pipe coil 31 `is dimensioned in cross section and length so as to occupy a substantial part of the hot-water reservoir space, at least more than half thereof, to be able quickly to transfer the heat from the hot water of the lreservoir to the fresh water in the pipe space.

According to Fig. 5 the hot-water reservoir 9, 12 of annular cross section may be replaced by a steam reser- Voir 34, in which the pipe coil 31 for the water for consumption is partly immersed into the hot reservoir water and partly extends through the steam space, from which the steam can ilow through the riser pipe 27 into the heat ing line to the radiators.

It should be emphasized above all that the entire plant is controlled by a control member under control of a thermostat 35 arranged in the hot-water reservoir 9 or low-pressure steam reservoir 34. That thermostat 35 is incorporated in the hot-water reservoir so as to be easily removable and adjacent to the cold-water inlet to pipe coil 31 and the reservoir outlet 13 and for this reason is temperature-controlledby the inowing cold water in the pipe coil and by the cooled-down hot water of the reservoir. Where a hot-water reservoir is used, `according to Fig. l, the thermostat 35 is functionally connected through a control line 38 to a gas pressure control 17 of the gas burner 14 and controls the gas pressure control 17 in dependence on the degree to which the thermostat is cooled by the fresh water and/or the outowing reservoir water. Where a low-pressure steam reservoir 34 is employed (Fig. 5), the thermostat 35 will intiuence under the same conditions the steam pressure control (not shown) which is `also connected through a control line to the gas pressure control 17 and operates the same to throttle it or to eiect a greater or smaller increase of the heating eiect of the gas tiring. The location of the thermostat 35 in the hot-water or steam reservoir s of eminent importance for the ability of the ow heater quickly to respond to the respective conditions of demand for water consumption and room heating.

This means that the flow heater is capable of regulating itself fully automatically and to adapt automatically with highest economic eiiciency to the heat consumption resulting at any time from the heating of water for consumption and from room heating, without being dependent on the pressure conditions in the local water supply.

The tlow heater has the following mode of operation: It may be assumed that the heater 1 and the hotwater reservoir 9, 12 be lled with water and the burner be in operation. The heating gases flow within the trebox casing 24 upwardly along the heating elements 1 until they are detiected by the baes 26 through the passages slots 2 into the respective adjacent interspace and can escape around the reservoir shell outwardly through the offtake 25 into the flue 37. The heat absorbed by the heating elements 1 is transferred to the water which flows through the conduits 3 and in the form of hot water or steam flows through the delivery pipe 8 to the hot-water reservoir 9, 12 or steam reservoir 34. Here the hot fluid brings the pipe coil 31 with its contents of Water for consumption to the same temperature as the water contained in the reservoir 9, 12. When the reservoir water has been cooled because heated water for consumption has been taken from the sumption can be effected with this ow heater simultaneously though completely independently of each other. It is of eminent importance that the flow heater` according to the invention, owing to its design, is independent of the pressure conditions in the local water supply and for this reason can be reduced down to a minimum from a normal heat output without need for giving regard to the pressure conditions in the water supply. Thus it is achieved for the tirst time that a flow heater of relatively small size but high heat transfer rate can be used for winter and summer operation without requiring changes in the flow system of the hot-water cycle or in the burner system. Whereas in winter operation the riser pipe and the following supply line 3i) supply hot water to the radiators for room heating, the riser pipe 27 will function in summer operation only as an expansion tube with overtlow vessel and the hot-water reservoir 9, 12 will serve only for heating the water for consumption, which flows through the pipe coil 21 as required.

In addition, the heat output can be reduced or increased by a subdivision of the heating elements 1 into element groups that can be connected and disconnected. in order to increase the heating effect with unchanged reservoir 9, 12, it-is possible to connect additionally instead of one group of heating elements a plurality of clement groups of the same heat output and connected in parallel in the hot-water cycle.

I claim:

1. A heating system comprising, in combination, a tank having two ends; inlet means for heated Huid located at one of said ends of said tank; first outlet means at the other end of said tank for discharging the iluid; conduit means including heater means connecting said first outlet means with said first inlet means for heating fluid circulating through said conduit means and said tank; second outlet means located on said tank intermediate said inlet means and said first outlet means in a position nearer to said inlet means than said first outlet means, said second outlet means being adapted to be connected to a domestic heating system for supplying to the same hot fluid from said tank; and water pipe means in said tank extending between said ends of said tank and having an inlet for cold water and an outlet for water heated in said tank during passage through said water pipe means, said outlet being adapted to be connected to a domestic water supply system, a portion of said water pipe means being located intermediate said inlet means and said second outlet means of said tank so as to utilize for the domestic water supply system at least part of the heat of the fluid passing from said inlet means into said second outlet means when hot water is discharged from said outlet of said water pipe means and cold water flows into said inlet and through said portion of said pipe means.

2. A heating system comprising, in combination, a tank having two ends; inlet means for heated fluid located at one of said ends of said tank; first outlet means at the other end of said tank for discharging the fluid; conduit means including heater means connecting said first outlet means with said first inlet means for heating fluid circulating through said conduit means and said tank; second outlet means locatedron said tank intermediate said inlet means and said first outlet means in a position nearer to said inlet means than said first outlet means, said second outlet means being adapted to be connected to a domestic heating system for supplying to the same hot fluid from said tank; and water pipe means in said tank extending between said ends of said tank and having an inlet for cold water and an outlet for water heated in said tank during passage through said water pipe means, said outlet being adapted to be connected to a domestic Waterf supply system, said inlet and said outlet of said water pipe means being located at said other end of said tank and remote from said first inlet means, a portion of said water pipe means being located intermediate said inlet means and said second outlet means of said tank so as to utilize for the domestic water supply system at least part of the heat of the fluid passing from said inlet means into said second outlet means when hot water is discharged from said outlet of said water pipe means and cold water flows into said inlet and through said portion of said pipe means.

3. A heating system as set forth in claim 2 and including a thermostat means located in said tank adjacent said inlet of said water pipe means and said first outlet means so as to be controlled by the temperature of cold water passing through said inlet and by the temperature of fluid discharged from said first outlet means, said thermostat means being adapted to control the temperature of heated fluid supplied from said heater means to said inlet means of said tank.

4. A heating system comprising, in combination, a tank having two ends; inlet means for heated fluid located at one of said ends of said tank; first outlet means at the other end of said tank for discharging the fluid; conduit means including heater means connecting said first outlet means with said first inlet means for heating fluid circulating through said conduit means and said tank; second outlet means located on said tank intermediate said inlet means and said first outlet means in a position nearer to said inlet means than said first outlet means, said second outlet means being adapted to be connected to a domestic heating system for supplying to the same hot fluid from said tank; and water pipe coil means in said tank extending between said ends of said tank and having an inlet for cold water and an outlet for water heatc d in said tank during passage through said water pipe coil means, said outlet being adapted to be connected to a domestic water supply system, a portion of said water pipe coil means including a plurality of turns of said water pipe coil means being located intermediate said inlet means and said second outlet means of said tank so as to utilize for the domestic water supply system at least part of the heat of the fluid passing from said inlet means into said second outlet means when hot water is discharged from said outlet of said water pipe means and cold water flows into said inlet and through said portion of said pipe coil means. v

5. A heating system comprising, in combination, a tank having two ends; inlet means for heated fluid located at one of said ends of said tank; first outlet means at the other end of said tank for discharging the fluid; conduit means including heater means connecting said first outlet means with said first inlet means for heating fluid circulating through said conduit means and said tank; second outlet means located on said tank intermediate said inlet means and said first outlet means in a position nearer to said inlet means than said first outlet means, said second outlet means being adapted to be connected to a domestic heating system for supplying to the same hot fluid from said tank; and water pipe coil means in said tank extending between said ends of said tank and having an inlet for cold water and an outlet for water heated in said tank during passage through said water pipe coil means, said outlet being adapted to be connected to a domestic water supply system, said inlet and said outlet of said water pipe means being located at said other end of said tank and remote from said first inlet means, a portion of said water pipe coil means including a plurality of turns of said water pipe coil means being located References Cited in the file of this patent UNITED STATES PATENTS 1,730,293 Reed et al Oct. 1, 1929 1,769,265 Labus July 1, 1930 1,908,042 Moore May 9, 1933 1,910,565 Refsgaard May 23, 1933 1,925,398 Moore Sept. 5, 1933 2,151,108 Hultgren Mar. 21, 1939 2,159,284 Miller May 23, 1939 2,189,749 Windheim et al Feb. 13, 1940 2,327,339 Chandler Aug. 24, 1943 2,399,985 Chandler May 7, 1946 2,592,216 Watts Apr. 8, 1952 2,607,535 Moore Aug. 19, 1952 2,617,392 Donohue Nov. 11, 1952 FOREIGN PATENTS 753,108 France July 31, 1933 

